Magnetically oriented pigment particles in a printed and cured ink are known as a security feature for the protection of value documents. Particular magnetic devices and processes for producing said security features are known as well, e.g. from EP-B 1 641 624, WO-A 2006/061301, WO-A 2008/009569, and WO-A 2008/046702. An industrial screen-printing machine for the rotary printing of said security features has been disclosed in WO-A 2005/000585. In said machine, the screen-printing units and the magnetic orienting devices have, both, the form of rotary drums.
WO-A 2005/000585 discloses a stand-alone rotary magnetic orienting device, which can be used subsequent to a printing process, e.g. as an additional process station following e.g. a conventional flat-bed screen printing unit, in order to impose a particular orientation to magnetic or magnetizable pigment particles comprised in a freshly printed ink, prior to hardening (drying, curing) said ink. Optically variable magnetic pigment particles are known from U.S. Pat. Nos. 4,838,648 and 6,875,522.
No magnetic orienting device combining a flat-bed screen-printing unit with a magnetic orienting unit in a single process station has, however, been disclosed up to now. On the other hand, flat-screen flat-bed screen-printing equipment being of extended industrial use, there is a long-felt need for a magnetic orienting unit adapted to work with this type of printing equipment.